Harvesting and subsequent processing, packaging and storage of produce evokes a strong response of the plant material which in general leads to a fast reduction of the quality of the end product. Quality in this respect refers to several attributes, for example, color, taste, smell, and crispness, which is perceived by the consumer as freshness.
The response of produce towards processing may be of a combined physical, biochemical and physiological nature resulting in wilting, discoloration and senescence. In order to improve the quality of processed produce it will become increasingly important to develop plant varieties which show reduced levels of deterioration as a consequence of processing.
Lettuce is currently one of the fresh products that is increasingly offered to the consumer in a processed (e.g., cut, washed, packaged) form. This ready-to-eat product contributes to the convenience of the consumer and allows the development of new products like mixes of different leafy or other types of vegetables.
The most important problem that occurs during lettuce processing and storage is the wound surface discoloration. This disorder manifests as a pink or brown coloration at the wound surface of the cut leaves. The mid rib sections are especially prone to a strong staining in this respect. This negative quality trait is the most important trait to be controlled during processing, as packaged lettuce with a pink or brown discoloration is perceived by the consumer as a deteriorated product.
Although post-harvest treatments, for example, packaging under a controlled atmosphere, typically prevent discoloration and have improved the quality of fresh cut, packaged lettuce, a genetic solution is preferred. The reasons are that despite these treatments, a substantial part of the product is still lost due to causes such as damaged packages. Also shelf life after opening the package by the end user is typically very short, and, importantly, there is significant cost involved.
Therefore, breeding for lettuce plants that have improved processing traits, in particular reduced surface discoloration, is important for the lettuce processing industry. The same applies to the processing of other plant material, such as witloof and eggplant.
It is thus the object of the invention to enable the fast and efficient identification of plant material that has a reduced surface discoloration for use thereof in the production of crop plants that are less prone to post-harvest deterioration.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.